The University of Pennsylvania Cancer Center seeks to establish a formal Research Program in Breast Cancer, with an emphasis on molecular genetics, during the next four-year period. The resources provided through the NCl's P20 (Option A) grant mechanism will be used to Create the administrative and research infrastructure for this program, including the appointment of a well-qualified Program Development Director, funding of Pilot Projects in areas targeted for development (e.g., translational research, high priority subpopulations), and recruitment of New Investigators needed for the successful realization of unified, programmatic effort in breast cancer research at the Cancer Center. While the Cancer Center has a nucleus of funded investigators conducting research in breast cancer, there continues to be no unified, organized, integrated or sustained approach to conducting interdisciplinary breast cancer research. Breast cancer research has largely resulted from the personal interest of individual members, rather than from any organizational effort. Without the programmatic framework and scientific aims that are essential components of Research Programs, breast cancer research continues to lack cohesion and focus. The University of Pennsylvania Cancer Center and the University of Pennsylvania Medical Center are fully committed to establishing the Breast Cancer Program described in this application. Breast Cancer was selected as a research and clinical priority of the Cancer Center through institutional and internal strategic planning process in 1992. As a result of this planning process, Barbara L. Weber, M.D., was recently recruited as Program Development Director of the Cancer Center's planned Breast Cancer Program. Dr. Weber is a well-funded molecular geneticist and recognized expert in the field of breast cancer genetics who is currently conducting research in BRCA1 positional cloning, has been actively involved in the planning of the Breast Cancer Program at Penn and has directed the preparation of this P20 grant application. Given her extensive background in laboratory investigation of the molecular genetics of breast cancer, clinical trials, and multidisciplinary and multi-institutional programmatic initiatives, Dr. Weber is well-qualified to assume the role of Program Development Director. Hence, the University of Pennsylvania Cancer Center possesses the organizational capabilities, qualified Program Development Director, carefully developed plan, nucleus of investigators and resources, and institutional commitment to establish and sustain a program in Breast Cancer. Without the funding and stimulus provided by the P20, investigation in breast cancer will remain fragmented and spread among the Center's existing Research Programs, and the ability of Center members to conduct significant breast cancer research will not be fully realized. With the availability of the P20 grant mechanism, the Cancer Center will have the resources to create an comprehensive Research Program in Breast Cancer that has an emphasis on the genetics of breast cancer